Question: A PDO object called `$db` has been set up to use for database operations, including user authentication. All user-related properties are set. The script line `public function __construct(&$db)` shows a constructor that initializes all user-related properties to \_ if no user has logged in. These parameters will be properly set by the login functions when a user logs in.
- NULL
- TRUE
- FALSE
- 0
Answer: The correct answer of the above question is Option A:NULL